METHOD OF PROTECTING INSULATION COATING ON ZIRCONIUM Russian patent published in 2013 - IPC C25D11/26 

FIELD: chemistry.

SUBSTANCE: method involves anodic oxidation of a zirconium sample in an electrolyte with addition of a fluorine-containing component, wherein anodic oxidation is carried out in two steps, at the first step in an anhydrous electrolyte containing fluorides, at current density of 10-20 mA/cm² and voltage of 95-130 V; the sample is then subjected to cathodic polarisation in 4% aqueous boric acid solution with addition of 25% ammonia solution, at voltages which correspond to the first anodic oxidation step; the sample is then washed in distilled water and dried; at the second step the zirconium undergoes anodic oxidation in the electrolyte in which cathodic polarisation was carried out, with constant current density of 1-5 mA/cm² an voltage of 200-300 V.

EFFECT: obtaining dimensional, solid, stable anode coatings on zirconium.

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